Load management system and method for motor vehicle restraints

Abstract

A load management system and method for controlling the activation sequence and times of activation of motor vehicle occupant restraints when a high g event, such as a crash, occurs. The system includes a microprocessor that processes inputs from a number of devices including seat weight sensor, an occupant spatial position detector, a buckle status detector, a belt sensor. The microprocessor is driven by a load management procedure that includes a high g event routine that controls the activation sequence of restraints so that the automatic locking restraint is first activated, followed by the pre-tensioner and then by the air bag. The load management procedure also includes an enable/disable procedure that controls the enabling and disabling of the restraints according to a number of variables including occupant weight, seat buckle status and belt extension status.

1. A method of managing the enablement and disablement of occupant restraints in a motor vehicle, said method comprising:
 (a) determining if a seat belt of a seat is buckled or unbuckled;  
 (b) determining if a weight in the seat is less then a threshold weight or is equal to or greater than the threshold weight:  
 (c) in response to the determination of steps (a) and (b), enabling at least one occupant restraint of the group that consists of an automatic locking restraint, a pre-tensioner and an air bag,  
 (d) if the seat belt is buckled and the weight in the seat is less than threshold weight, disabling the air bag and activating the automatic locking restraint upon sensing a high g event, and activating the pre-tensioner after activating the automatic locking restraint;  
 (e) if the seat belt is unbuckled and the weight in the seat is less than the threshold weight, disabling the air bag and the pre-tensioner;  
 (f) if the seat belt is unbuckled and the weight in the seat is equal to or greater than the threshold weight, disabling the pre-tensioner and activating air bag upon sensing a high g event; and  
 (g) if the seat belt is buckled and the weight in the seat is equal to or greater than the threshold weight, activating the automatic locking restraint upon sensing a high g event, activating the pre-tensioner after activating the automatic locking restraint, and activating the air bag after activating the pre-tensioner.  
 
   
   
     2. The method of  claim 1 , further comprising:
 (h) if step (a) determines that the seat belt is buckled and step (b) determines that said weight in said seat is equal to or greater than said threshold, determining if the seat belt is extended and, if not, performing step (g); and  
 (i) if step (h) determines that the seat belt is extended, disabling said air bag and enabling said automatic locking restraint and said pre-tensioner.  
 
   
   
     3. The method of  claim 1 , further comprising:
 (j) if step (a) determines that the seat belt is buckled and step (b) determines that said weight in said seat is less than said threshold, enabling said air bag to inflate with a procedure that provides a soft inflation impact on said occupant.  
 
   
   
     4. The method of  claim 3 , further comprising signaling an alert if step (j) is performed. 
   
   
     5. The method of  claim 1 , further comprising:
 (k) determining a weight in said seat as measured by a weight sensor system;  
 (l) if said weight is greater than a threshold weight, determining if said seat belt is tightened;  
 (m) if step (l) determines that said seat belt is tightened, determining an adjusted weight; and  
 wherein step (c) enables said at least one occupant restraint dependent on a comparison of said adjusted weight and said threshold weight.  
 
   
   
     6. The method of  claim 5 , wherein step (l) determines seat belt tightening by comparing values measured by said sensor system at about the rear right and rear left of said seat. 
   
   
     7. The method of  claim 6 , wherein step (m) derives said adjusted weight from said values. 
   
   
     8. The method of  claim 7 , wherein step (m) determines said adjusted weight only if the difference between said values is greater than a predetermined amount. 
   
   
     9. The method of  claim 5 , wherein steps (l) and (m) are repeated until a predetermined time has expired from the time the seal has been buckled. 
   
   
     10. The method of  claim 5 , further comprising:
 (n) if step (a) determines that the seat belt is buckled and step (b) determines that said weight in said seat is equal to or greater than said threshold, determining if the seat belt is extended and, if not, performing step (d); and  
 (o) if step (n) determines that the seat belt is extended, enabling a manual locking restraint.  
 
   
   
     11. The method of  claim 10 , further comprising:
 (p) enabling said air bag with an inflation procedure that provides a soft inflation impact on said occupant.  
 
   
   
     12. A system for managing the enablement and disablement of occupant restraints on an occupant in a seat having a seat belt in a motor vehicle, said system comprising:
 a plurality of occupant restraints selected from the group consisting of an automatic locking restraint, a pre-tensioner and an air bag device;  
 a processor, a memory and a bus that interconnects said processor, said memory and said plurality of occupant restraints;  
 a load management procedure stored in said memory that controls said processor to perform the following steps: 
 (a) determining if said seat belt is buckled or unbuckled;  
 (b) determining if a weight in the seat is less than a threshold weight or is equal to or greater than the threshold weight;  
 (c) in response to the determination of steps (a) and (b), enabling at least one said occupant restraints;  
 (d) if the seat belt is buckled and the weight in the seat is less than threshold weight, disabling the air bag and activating the automatic locking restraint upon sensing a high g event, and activating the pre-tensioner after activating the automatic locking restraint;  
 (e) if the seat belt is unbuckled and the weight in the seat is less than the threshold weight, disabling the air bag and the pre-tensioner;  
 (f) if the seat belt is unbuckled and the weight in the seat is equal to or greater than the threshold weight, disabling the pre-tensioner and activating the air bag upon sensing a high g event: and  
 (g) if the seat belt is buckled and the weight in the seat is equal to or greater than the threshold weight, activating the automatic locking restraint upon sensing a high g event, activating the pre-tensioner after activating the automatic locking restraint, and activating the air bag after activating the pre-tensioner.  
 
 
   
   
     13. The system of  claim 12 , said load management procedure further comprising:
 (h) if step (a) determines that the seat belt is buckled and step (b) determines that said weight in said seat is equal to or greater than said threshold, determining if the seat belt is extended and, if not, performing step (g); and  
 (i) if step (h) determines that the seat belt is extended, disabling said air bag and enabling said automatic locking restraint and said pre-tensioner.  
 
   
   
     14. The system of  claim 12 , said load management procedure further comprising:
 (j) if step (a) determines that the seat belt is buckled and step (b) determines that said weight in said seat is less than said threshold, enabling said air bag to inflate with a procedure that provides a soft inflation impact on said occupant.  
 
   
   
     15. The system of  claim 14 , said load management procedure further comprising signaling an alert if step (j) s performed. 
   
   
     16. The system of  claim 12 , said load management procedure further comprising:
 (k) determining a weight in said seat as measured by a weight sensor system;  
 (l) if said weight is greater than a threshold weight, determining if said seat belt is tightened;  
 (m) if step (l) determines that said seat belt is tightened, determining an adjusted weight; and  
 wherein step (c) enables said at least one occupant restraint dependent on a comparison of said adjusted weight and said threshold weight.  
 
   
   
     17. The system of  claim 16 , step (l) determines seat belt tightening by comparing values measured by said sensor system a:about the rear right and rear left of said seat. 
   
   
     18. The system of  claim 17 , wherein step (m) derives said adjusted weight from said values. 
   
   
     19. The system of  claim 18 , wherein step (m) determines said adjusted weight only if the difference between said values is greater than a predetermined amount. 
   
   
     20. The system of  claim 16 , wherein steps (l) and (m) are repeated until a predetermined time has expired from the time the seat has been buckled. 
   
   
     21. The system of  claim 12 , said load management procedure further comprising:
 (n) if step (a) determines that the seat belt is buckled and step (b) determines that said weight in said seat is equal to or greater than said threshold, determining if the seat belt is extended and, if not, performing step (g); and  
 (o) if step (n) determines that the seat belt is extended, enabling a manual locking restraint.  
 
   
   
     22. The system of  claim 21 , said load management procedure further comprising:
 (o) enabling said air bag with an inflation procedure that provides a soft inflation impact on said occupant.